This invention relates generally to a shoe or shoe mechanism utilized with an excavating wheel and associated method and, more particularly, to a pair of outer shoe/shield assemblies operatively positioned in association with the excavating wheel of a dredging apparatus for removing silt from the bottom of a body of water, the dredging apparatus being operable in both a forward and a reverse direction of travel.
Various types of dredging apparatus are well known in the art for removing silt, sand, mud or other sediment from the bottom of a body of water. One such dredging apparatus is disclosed in U.S. Pat. No. 5,960,570 and includes a floatation arrangement operative to float on the surface of the body of water, a frame structure mounted on the floatation arrangement, and a silt excavating wheel mechanism rotatably mounted to the frame structure and operative to extract silt from under the body of water. Such apparatus also typically includes a height adjustment mechanism operative to raise and lower the excavating wheel mechanism relative to the surface of the water and may include a conveyor arrangement operative to transport the extracted silt away from the excavating wheel mechanism.
Typically, the dredging apparatus and its associated excavating wheel are designed and constructed such that the dredging operation takes place in one predetermined direction such as in the forward direction of travel of the dredging apparatus. As a result, only a portion of the excavating wheel assembly must be shielded from the volume of water on the trailing side thereof between the silt located under the body of water and a point located above the water level. Since dredging only occurs in one direction, the known shoe or shield mechanisms such as the shield mechanism disclosed in U.S. Pat. No. 5,960,570 are always positioned and located adjacent the wheel assembly in an operative position and such known shoe mechanisms are not movable to an inoperative or retracted position. A retracted position is advantageous when the dredging apparatus is being maneuvered to and from the dredging location so as to avoid excessive wear and tear and/or damage to both the shoe and wheel mechanisms In addition, the forward or leading side of known excavating wheel assemblies do not include a shoe or shield mechanism thereby preventing dredging in the reverse direction.
Accordingly, the present invention is directed to overcoming one or more of the problems as set forth above.
In one aspect of the present invention, a shoe mechanism adapted for use on a dredging apparatus to remove silt from under the surface of a body of water, the dredging apparatus being operative in a forward and reverse direction and including an excavating wheel assembly, the excavating wheel assembly having an innermost and an outermost circumference, top and bottom portions, and a plurality of silt retaining chambers, the excavating wheel assembly being rotatably mounted on a wheel frame assembly to define a leading side and a trailing side of the wheel assembly when the apparatus is operative in its forward or reverse direction is disclosed. The shoe mechanism includes a pair of outer shoe assemblies pivotally connected to the wheel frame assembly, one of said shoe assemblies being located adjacent a portion of the excavating wheel assembly on the leading side thereof and one of said shoe assemblies being located adjacent a portion of the excavating wheel assembly on the trailing side thereof, each of said outer shoe assemblies being pivotally movable between an operative position wherein said shoe assembly is positioned adjacent the outermost circumference of the wheel assembly between the silt under the body of water and a point above the water level, and a retracted position wherein said shoe assembly is positioned in spaced apart relationship from the outermost circumference of the wheel assembly, one of said outer shoe assemblies being positioned in its operative position and the other of said outer shoe assemblies being positioned in its retracted position when the dredging apparatus is removing silt from under the surface of a body of water.
In another aspect of the present invention, a method for removing silt from under the surface of a body of water using a dredging apparatus operative in both a forward and reverse direction, the dredging apparatus including an excavating wheel assembly having an innermost and an outermost circumference and a plurality of silt retaining chambers, the excavating wheel assembly being rotatably mounted on a wheel frame assembly to define a leading side and a trailing side of the wheel assembly when the apparatus is operative in its forward or reverse direction is disclosed. The method includes the following steps: attaching a pair of outer shoe assemblies to the wheel frame assembly, one of said shoe assemblies being located adjacent a portion of the excavating wheel assembly on the leading side thereof and one of said shoe assemblies being located adjacent a portion of the excavating wheel assembly on the trailing side thereof; enabling each of said outer shoe assemblies to be pivotally movable relative to the wheel assembly, each of said outer shoe assemblies being pivotally movable between an operative position wherein said shoe assembly is positioned adjacent the outermost circumference of the wheel assembly between the silt under the body water and a point above the water level, and a retracted position wherein said shoe assembly is positioned in spaced apart relationship from the outermost circumference of the wheel assembly; determining the direction of travel of the dredging apparatus for a particular dredging operation; determining the leading side and trailing side of the wheel assembly based upon the direction of travel of the dredging apparatus for the particular dredging operation; positioning the shoe assembly disposed on the trailing side of the excavating wheel assembly in its operative position prior to commencing the particular dredging operation; and positioning the shoe assembly disposed on the leading side of the excavating wheel assembly in its retracted position prior to commencing the particular dredging operation.